Note 6 - Goodwill and Intangibles - Changes in Goodwill (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Goodwill, gross $ 226,889 $ 231,999 $ 233,877
Accumulated impairment losses (107,265) (102,041) (102,041)
Goodwill 119,624 129,958 131,836
Foreign currency translation adjustment (5,110) (1,878)  
Asset impairment charge (5,224)    
NET Services [Member]      
Goodwill, gross 191,215 191,215 191,215
Accumulated impairment losses (96,000) (96,000) (96,000)
Goodwill 95,215 95,215 95,215
Foreign currency translation adjustment  
Asset impairment charge    
WD Services [Member]      
Goodwill, gross 35,674 40,784 42,662
Accumulated impairment losses (11,265) (6,041) (6,041)
Goodwill 24,409 34,743 $ 36,621
Foreign currency translation adjustment (5,110) $ (1,878)  
Asset impairment charge $ (5,224)